The university of Utah posts a streaming video course about "launchd"

James gave an overview of launchd and how it will change your implementation of startup, login & logout scripts. He also demonstrated Launchd Editor, which is a graphical editor for launchd property list files.

Launchd, in case you didn't know, is the reason your computer boots so much quicker in Tiger than it did in Panther. The first time I saw my new iMac boot up in around 20 seconds I had to change my underwear. Launchd will hopefully replace a motley crew of daemons and scripts and bring all launching services under a single umbrella.

I've not personally watched this video — I'm not allowed to have Quicktime at work ;( — but I'm told its pretty good and instructional, especially for those of us who learn better when someone else teaches us the information rather than just reading about it on a webpage somewhere.